Generally, a sigma-delta analog digital converter (ADC) runs at a high frequency and is associated with one or more reference buffers or buffers. For example, a reference voltage provided by a reference buffer is generally required for the sigma-delta ADC. Generally, a reference buffer comprises a buffer offset or offset, which is generally undesirable. In an example, the buffer offset impacts an ADC curve such that the ADC curve is different from a theoretical ADC curve. Implementing an increased buffer size or a switched capacitor for storing the buffer offset mitigates at least some of the buffer offset. However, an increased buffer size generally increases circuit area. In some examples, it is undesirable to increase circuit area according to design rules. Additionally, the switched capacitor requires a high driving input signal, additional power, large capacitors to store the buffer offset, and is thus difficult to implement.